im thinking of doing a home made lift on the old truck to thank it for pulling a dmax i was thinking of putting 4 inch steel blocks under the springs since my springs are flat not negative or positive arch 4 inch should go without having to put shocks longer or brake hoses what you all think

 

front blocks are a very bad idea.

The rear probably already has 4-6" blocks from the factory as well. My 93 has stock 6" ones.

 

Y are front blocks bad idea

 

They can losen up the long u-bolts causing them to break or shoot out, causing you to loose control of the truck. In Most states if not all state Front lift block are illegal.

 

What Terraizer said, plus adding lift blocks on the front will give the axle more leverage to twist the springs (spring wrap) under braking which in turn changes the steering geometry and can create some scary handling issues. IE: Hit the brakes hard = automatic lane change.

I did a 2in. lift on mine with new springs and the drive shaft and brake lines were OK. If you want a cheap way to raise the truck without a major thrash go down to your local Autozone or Pepboys and get a set of those coil springs that slip over the shocks and are held on with muffler clamps. I've run those on the rear of 1/2 ton trucks with pretty good results. Just adjust the clamps until you get the lift you want. Not pretty, but effective. They come in different spring rates, I'd get the heaviest ones they have.

 

looks like you need to give skyjacker a call